Future portable radio products are being designed to accommodate multiband platforms providing operation over two or more frequency bands. A single handset that can seamlessly operate in the VHF, UHF and 700-800 MHz bands would be highly beneficial. One of the challenges in the transmitter section of such a product is to design a power amplifier that can operate from 100 MHz to 900 MHz.
One approach to the multiband challenge is to include complete amplifier lineups for each band and switch them in or out accordingly. While several components can be re-used in different bands, two or more final stage FETs are needed to cover all the bands which presents issues with packaging and thermal dissipation size relative to size, cost and space constraints.
One current multiband amplifier approach utilizes multiple substrates, individually tested and mounted in a common substrate-mounting frame. Another approach takes a single active device and several passive components comprising a single PA final stage with one set of pads for the RF signal. Both of these approaches, however, are limited in their ability to provide precise biasing and scaling in size.
Accordingly, there is a need for an improved packaging assembly for electronic components, and particularly an assembly that facilitates multiband applications.